JP5568342B2 - Semiconductor device manufacturing method, substrate processing method, and substrate processing system - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor device having a step of processing a substrate in a processing container, and a substrate processing system suitably used in the step.

  In recent years, with the miniaturization of semiconductor devices, metal films other than Si are being used instead of Si-based metal films, for example, as gate electrodes and source / drain lead electrodes. As a method for forming a metal film other than Si, a metal-organic chemical vapor deposition (MOCVD) method in which a gas obtained by vaporizing a liquid raw material containing metal and a reaction gas are supplied to a substrate, or ALD (Atomic Layer Deposition). ) Or similar methods are used.

However, when the above-described metal film is formed using a liquid source, the growth rate is significantly affected by the surface condition of the base, for example, the thin film does not grow or incubation occurs, and the timing of film formation rises. In some cases, the growth may become unstable. For example, when a liquid film is used to form a metal film such as aluminum (Al) on a titanium nitride (TiN) film, the underlying TiN surface is exposed, and the underlying TiN surface is titanium oxide ( In some cases, the film formation rate was different from the case of being covered with TiO ₂ ) or titanium oxynitride (TiON). This is presumably because a metal material such as Al is easily adsorbed on a conductive film such as TiN and is difficult to adsorb on an insulating film made of an oxide or the like.

  An object of the present invention is to provide a method of manufacturing a semiconductor device and a substrate processing system capable of stably growing a metal film other than Si using a liquid raw material.

  According to one aspect of the present invention, a step of performing a first pretreatment for terminating the surface of a first metal film formed on a substrate with a hydroxyl group, and the first metal after the first pretreatment Supplying a hydrogen-containing gas to the film and performing a second pretreatment; and forming a second metal film on the first metal film after the second pretreatment. A method for manufacturing a semiconductor device is provided.

  According to another aspect of the present invention, the first processing container for processing the substrate, the HF aqueous solution supply system for supplying the HF aqueous solution into the first processing container, and the first processing container accommodated in the first processing container. A first control unit that controls the HF aqueous solution supply system to supply a HF aqueous solution to the substrate and to perform a first pretreatment for terminating the surface of the first metal film formed on the substrate with a hydroxyl group. A second processing container that processes the substrate, a hydrogen-containing gas supply system that supplies a hydrogen-containing gas into the second processing container, and a source gas supply that supplies a source gas into the second processing container A second pretreatment is performed on the first metal film after the first pretreatment by supplying a hydrogen-containing gas to the system and the substrate accommodated in the second treatment container; The source gas is supplied to the substrate and the first metal film after the second pretreatment is applied. So as to form a second metal layer, and a second control unit for controlling the hydrogen-containing gas supply system and the raw material gas supply system, a substrate processing apparatus having a provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method and substrate processing apparatus of a semiconductor device which can be made to grow stably metal films other than Si using a liquid raw material can be provided.

It is a flowchart of the substrate processing process concerning one Embodiment of this invention. (A) is a schematic side view of the 1st processing unit 31 concerning one embodiment of the present invention, and (b) is a section lineblock diagram of the 1st processing unit 31. It is a block diagram of the gas supply system and exhaust system which the 2nd processing unit 32 concerning one Embodiment of this invention has. It is a section lineblock diagram at the time of wafer processing of the 2nd processing unit 32 concerning one embodiment of the present invention. It is a section lineblock diagram at the time of wafer conveyance of the 2nd processing unit 32 concerning one embodiment of the present invention. It is a schematic block diagram of the vertical processing furnace of the vertical CVD apparatus as the 2nd processing unit 32 concerning other embodiment of this invention, (a) shows the processing furnace 302 part in a longitudinal cross-section, (b) is The process furnace 302 part is shown by the AA line sectional view of (a). It is a figure which shows the surface state of the TiN film | membrane after implementing a 1st pre-processing process and a 2nd pre-processing process. It is a figure which shows the electron microscope image of the evaluation sample in the Example and comparative example of this invention.

<One Embodiment of the Present Invention>
Hereinafter, a configuration of a substrate processing system according to an embodiment of the present invention and a substrate processing process as one process of a semiconductor device manufacturing process performed by the substrate processing system will be described.

  The substrate processing system according to the present embodiment implements a first processing unit that performs a first preprocessing step described later, a second preprocessing step described later, and a step of forming a second metal film. And a processing unit. The first processing unit is configured as a cleaning device, and the second processing unit is configured as a CVD device. Below, the structure of a 1st processing unit and a 2nd processing unit is demonstrated in order.

(1) Configuration of First Processing Unit First, the configuration of the first processing unit 31 according to the present embodiment configured as a cleaning apparatus, that is, the configuration of the first substrate processing apparatus will be described with reference to FIG. FIG. 2A is a schematic side view of the first processing unit 31 according to the embodiment of the present invention, and FIG. 2B is a cross-sectional configuration diagram of the first processing unit 31.

  As shown in FIG. 2, the first processing unit 31 according to the present embodiment has a cleaning apparatus body 112 as a first processing container for processing a wafer 200 such as a silicon wafer as a substrate. A cleaning chamber 114 for cleaning the wafer 200 is configured in the cleaning apparatus main body 112. A support 118 for horizontally supporting the wafer 200 is disposed in the cleaning chamber 114. The support 118 is connected to a rotation mechanism 120 made of a motor or the like via a rotation shaft 121. The rotating mechanism 120 rotates the wafer 200 that is horizontally supported.

  The periphery of the support 118 is surrounded by a cover 122. As will be described later, the cover 122 receives chemicals that fly from the wafer 200 when the wafer 200 is rotated by the support 118.

As shown in FIG. 2A, a substrate transfer port 124 is formed on the side surface of the cleaning apparatus main body 112. A gate valve 126 is provided at the substrate transfer port 124. The substrate transfer port 124 is opened and closed by the gate valve 126. In addition, a substrate transfer machine 127 that transfers the wafer 200 to the support 118 via the substrate transfer port 124 is provided outside the cleaning apparatus main body 112.

  The cleaning chamber 114 is provided with a cleaning liquid supply unit 128 that supplies a cleaning liquid such as a hydrogen fluoride (HF) aqueous solution, that is, dilute hydrofluoric acid obtained by diluting hydrofluoric acid with pure water (DHF (Diluted HF)), for example. The cleaning liquid supply unit 128 is horizontally arranged so that the tip (downstream end) extends to near the center of the wafer 200 supported by the support 118. The upstream side of the cleaning liquid supply unit 128 is connected to a cleaning liquid supply source 132 that supplies the cleaning liquid. The cleaning liquid supply unit 128 is provided with a control valve 132a for controlling the supply of the cleaning liquid. A cleaning liquid such as DHF is supplied from the cleaning liquid supply unit 128 toward the center of the wafer 200. The cleaning liquid supply unit 128, the cleaning liquid supply source 132, and the control valve 132a mainly constitute an HF aqueous solution supply system (HF aqueous solution supply line) as a cleaning liquid supply system (cleaning liquid supply line).

  The cleaning chamber 114 is provided with a rinsing water supply unit 130 for supplying rinsing water made of pure water (DIW (Deionized Water)), for example. The rinse water supply unit 130 is horizontally arranged so that the tip (downstream end) extends to near the center of the wafer 200 supported by the support 118. The upstream side of the rinse water supply unit 130 is connected to a rinse water supply source 134 that supplies rinse water. The rinse water supply unit 130 is provided with a control valve 134a for controlling the supply of rinse water. Rinse water such as pure water is supplied from the rinse water supply unit 130 toward the center of the wafer 200. The rinsing water supply unit 130, the rinsing water supply source 134, and the control valve 134a mainly constitute a pure water supply system (pure water supply line) as a rinsing water supply system (rinsing water supply line).

  The cleaning chamber 114 is provided with a water supply unit 140 that supplies water made of pure water (DIW). The front end (downstream end) of the water supply unit 140 opens around the inside upper portion of the cover 122 described above, and the other end (upstream end) is connected to a pure water supply source 142 that supplies pure water. The pure water can be supplied to the inner surface. The water supply unit 140 is provided with a control valve 142a for controlling the supply of pure water. A pure water supply system (pure water supply line) is mainly configured by the water supply unit 140, the pure water supply source 142, and the control valve 142a. The pure water supply source 142 may be shared with the rinse water supply source 134.

  A discharge pipe 144 that discharges the cleaning liquid and pure water supplied to the wafer 200 and the pure water supplied to the cover 122 is connected to the lower surface of the cover 122. The discharge pipe 144 extends to the outside of the cleaning device main body 112. The cleaning liquid and pure water in the cover 122 are discharged through the discharge pipe 144. The discharge pipe 144 is provided with a control valve 144a that controls the discharge of the cleaning liquid and pure water. A discharge system (discharge line) is mainly configured by the discharge pipe 144 and the control valve 144a.

A drying gas supply pipe 146 is connected to the upper part of the cleaning apparatus main body 112. A drying gas supply source 148 is connected to the upstream side of the drying gas supply pipe 146. The drying gas supply pipe 146 is provided with a control valve 148a for controlling the supply of the drying gas. For example, nitrogen (N ₂ ) gas is used as the drying gas. Further, an exhaust pipe 150 for exhausting the drying gas is connected to the lower part of the cleaning apparatus main body 112. The exhaust pipe 150 is provided with a control valve 150a for controlling the exhaust of the drying gas. An N ₂ gas supply system (N ₂ gas supply line) as a drying gas supply system (drying gas supply line) is mainly configured by the drying gas supply pipe 146, the drying gas supply source 148, and the control valve 148a. The An exhaust system (exhaust line) is mainly configured by the exhaust pipe 150 and the control valve 150a.

  The first processing unit 31 according to the present embodiment includes a first controller 180 as a first control unit that controls the operation of each unit of the first processing unit 31. The first controller 180 controls operations of the rotation mechanism 120, the gate valve 126, the substrate transfer device 127, the control valves 132a, 134a, 142a, 148a, 144a, 150a, and the like.

(2) Configuration of Second Processing Unit Next, the configuration of the second processing unit 32 according to the present embodiment configured as a CVD apparatus, that is, the configuration of the second substrate processing apparatus will be described with reference to FIGS. . 4 is a cross-sectional configuration diagram of the second processing unit 32 according to an embodiment of the present invention during wafer processing, and FIG. 5 is a diagram of the second processing unit 32 according to an embodiment of the present invention during wafer transfer. FIG.

<Processing chamber>
As shown in FIGS. 4 and 5, the second processing unit 32 according to the present embodiment includes a second processing container 202. The second processing container 202 is configured as a flat sealed container having a circular cross section, for example. The second processing container 202 is made of a metal material such as aluminum (Al) or stainless steel (SUS). A processing chamber 201 for processing a wafer 200 such as a silicon wafer as a substrate is formed in the second processing container 202.

<Support stand>
A support base 203 that supports the wafer 200 is provided in the processing chamber 201. For example, quartz (SiO ₂ ), carbon, ceramics, silicon carbide (SiC), aluminum oxide (Al ₂ O ₃ ), or aluminum nitride (AlN) is formed on the upper surface of the support base 203 that the wafer 200 directly touches. A susceptor 217 is provided as a support plate. In addition, the support base 203 incorporates a heater 206 as a heating means (heating source) for heating the wafer 200. Note that the lower end portion of the support base 203 passes through the bottom portion of the second processing container 202.

<Elevating mechanism>
Outside the processing chamber 201, an elevating mechanism 207b for elevating the support base 203 is provided. The wafer 200 supported on the susceptor 217 can be moved up and down by operating the lifting mechanism 207 b to raise and lower the support base 203. The support table 203 is lowered to the position shown in FIG. 5 (wafer transfer position) when the wafer 200 is transferred, and is raised to the position shown in FIG. 4 (wafer processing position) when the wafer 200 is processed. The periphery of the lower end portion of the support base 203 is covered with a bellows 203a, and the inside of the processing chamber 201 is kept airtight.

<Lift pin>
In addition, on the bottom surface (floor surface) of the processing chamber 201, for example, three lift pins 208b are provided so as to rise in the vertical direction. In addition, the support base 203 (including the susceptor 217) is provided with through holes 208a through which the lift pins 208b pass, at positions corresponding to the lift pins 208b. When the support table 203 is lowered to the wafer transfer position, as shown in FIG. 5, the upper end portion of the lift pin 208b protrudes from the upper surface of the susceptor 217, and the lift pin 208b supports the wafer 200 from below. Yes. When the support table 203 is raised to the wafer processing position, as shown in FIG. 4, the lift pins 208b are buried from the upper surface of the susceptor 217, and the susceptor 217 supports the wafer 200 from below. In addition, since the lift pins 208b are in direct contact with the wafer 200, it is desirable to form the lift pins 208b with a material such as quartz or alumina.

<Wafer transfer port>
On the inner wall side surface of the processing chamber 201 (second processing container 202), a wafer transfer port 250 for transferring the wafer 200 into and out of the processing chamber 201 is provided. The wafer transfer port 250 is provided with a gate valve 251. By opening the gate valve 251, the inside of the processing chamber 201 and the transfer chamber (preliminary chamber) 271 communicate with each other. The transfer chamber 271 is formed in a transfer container (sealed container) 272, and a transfer robot 273 that transfers the wafer 200 is provided in the transfer chamber 271. The transfer robot 273 is provided with a transfer arm 273 a that supports the wafer 200 when the wafer 200 is transferred. By opening the gate valve 251 with the support 203 lowered to the wafer transfer position, the transfer robot 273 can transfer the wafer 200 between the processing chamber 201 and the transfer chamber 271. Yes. The wafer 200 transferred into the processing chamber 201 is temporarily placed on the lift pins 208b as described above. A load lock chamber (not shown) is provided on the opposite side of the transfer chamber 271 from the side where the wafer transfer port 250 is provided, and the wafer 200 is placed between the load lock chamber and the transfer chamber 271 by the transfer robot 273. Can be transported. The load lock chamber functions as a spare chamber for temporarily storing unprocessed or processed wafers 200.

<Exhaust system>
An exhaust port 260 for exhausting the atmosphere in the processing chamber 201 is provided on the inner wall side surface of the processing chamber 201 (second processing container 202) on the opposite side of the wafer transfer port 250. An exhaust pipe 261 is connected to the exhaust port 260 via an exhaust chamber 260a. The exhaust pipe 261 has a pressure regulator 262 such as an APC (Auto Pressure Controller) that controls the inside of the processing chamber 201 at a predetermined pressure. A raw material recovery trap 263 and a vacuum pump 264 are connected in series in this order. An exhaust system (exhaust line) is mainly configured by the exhaust port 260, the exhaust chamber 260a, the exhaust pipe 261, the pressure regulator 262, the raw material recovery trap 263, and the vacuum pump 264.

<Gas inlet>
A gas inlet 210 for supplying various gases into the processing chamber 201 is provided on the upper surface (ceiling wall) of a shower head 240 described later provided in the upper portion of the processing chamber 201. The configuration of the gas supply system connected to the gas inlet 210 will be described later.

<Shower head>
A shower head 240 as a gas dispersion mechanism is provided between the gas inlet 210 and the processing chamber 201. The shower head 240 is a dispersion plate 240 a that disperses the gas introduced from the gas introduction port 210, and a shower plate that further uniformly disperses the gas that has passed through the dispersion plate 240 a and supplies it to the surface of the wafer 200 on the support table 203. 240b. The dispersion plate 240a and the shower plate 240b are provided with a plurality of vent holes. The dispersion plate 240 a is disposed so as to face the upper surface of the shower head 240 and the shower plate 240 b, and the shower plate 240 b is disposed so as to face the wafer 200 on the support table 203. Note that spaces are provided between the upper surface of the shower head 240 and the dispersion plate 240a, and between the dispersion plate 240a and the shower plate 240b, respectively, and the spaces are supplied from the gas inlet 210. Function as a first buffer space (dispersion chamber) 240c for dispersing the gas and a second buffer space 240d for diffusing the gas that has passed through the dispersion plate 240a.

<Exhaust duct>
A step portion 201a is provided on the side surface of the inner wall of the processing chamber 201 (second processing container 202). The step portion 201a is configured to hold the conductance plate 204 in the vicinity of the wafer processing position. The conductance plate 204 is configured as a single donut-shaped (ring-shaped) disk in which a hole for accommodating the wafer 200 is provided in the inner periphery. A plurality of discharge ports 204 a arranged in the circumferential direction with a predetermined interval are provided on the outer periphery of the conductance plate 204. The discharge port 204 a is formed discontinuously so that the outer periphery of the conductance plate 204 can support the inner periphery of the conductance plate 204.

  On the other hand, a lower plate 205 is locked to the outer peripheral portion of the support base 203. The lower plate 205 includes a ring-shaped concave portion 205b and a flange portion 205a provided integrally on the inner upper portion of the concave portion 205b. The recess 205 b is provided so as to close a gap between the outer peripheral portion of the support base 203 and the inner wall side surface of the processing chamber 201. A part of the bottom of the recess 205b near the exhaust port 260 is provided with a plate exhaust port 205c that exhausts (circulates) gas from the recess 205b to the exhaust port 260 side. The flange portion 205 a functions as a locking portion that locks on the upper outer periphery of the support base 203. When the flange portion 205 a is locked on the upper outer periphery of the support base 203, the lower plate 205 is moved up and down together with the support base 203 as the support base 203 is moved up and down.

  When the support table 203 is raised to the wafer processing position, the lower plate 205 is also raised to the wafer processing position. As a result, the conductance plate 204 held in the vicinity of the wafer processing position closes the upper surface portion of the recess 205b of the lower plate 205, and the exhaust duct 259 having the gas passage region inside the recess 205b is formed. . At this time, the inside of the processing chamber 201 is above the processing chamber 201 above the exhaust duct 259 and below the exhaust duct 259 by the exhaust duct 259 (the conductance plate 204 and the lower plate 205) and the support base 203. It will be partitioned into the lower part of the chamber 201. The conductance plate 204 and the lower plate 205 are made of materials that can be kept at a high temperature, for example, high temperature and high load resistance, in consideration of etching reaction products deposited on the inner wall of the exhaust duct 259 (self cleaning). Preferably, it is made of quartz for use.

  Here, the flow of gas in the processing chamber 201 during wafer processing will be described. First, the gas supplied from the gas inlet 210 to the upper portion of the shower head 240 enters the second buffer space 240d through the first buffer space (dispersion chamber) 240c through a large number of holes in the dispersion plate 240a, and further into the shower. It passes through a number of holes in the plate 240 b and is supplied into the processing chamber 201, and is uniformly supplied onto the wafer 200. The gas supplied onto the wafer 200 flows radially outward of the wafer 200 in the radial direction. The surplus gas after contacting the wafer 200 flows radially on the exhaust duct 259 located on the outer peripheral portion of the wafer 200, that is, on the conductance plate 204, radially outward of the wafer 200. Is discharged into the gas flow path region (in the recess 205b) in the exhaust duct 259. Thereafter, the gas flows through the exhaust duct 259 and is exhausted to the exhaust port 260 via the plate exhaust port 205c. By flowing the gas in this way, gas wraparound to the lower portion of the processing chamber, that is, the back surface of the support base 203 or the bottom surface of the processing chamber 201 is suppressed.

<Gas supply system>
Next, the configuration of the gas supply system connected to the gas inlet 210 described above will be described with reference to FIG. FIG. 3 is a configuration diagram of a gas supply system and an exhaust system included in the second processing unit 32 according to the embodiment of the present invention.

The gas supply system of the second processing unit 32 according to the embodiment of the present invention includes a bubbler as a vaporization unit that vaporizes a liquid material containing aluminum (Al) that is in a liquid state at room temperature, and vaporizes the liquid material with the bubbler. A raw material gas supply system for supplying the raw material gas into the processing chamber 201, a hydrogen-containing gas supply system for supplying a hydrogen-containing gas into the processing chamber 201, and a purge gas supply system for supplying a purge gas into the processing chamber 201 And have. Furthermore, the second processing unit 32 according to the embodiment of the present invention has a vent (bypass) system that exhausts the processing gas to bypass the processing chamber 201 without supplying the raw material gas from the bubbler into the processing chamber 201. . Below, the structure of each part is demonstrated.

<Bubbler>
Outside the processing chamber 201, a bubbler 220a is provided as a raw material container for storing a liquid raw material. The bubbler 220a is configured as a tank (sealed container) capable of containing (filling) a liquid source therein, and is also configured as a vaporizing unit that generates a source gas by vaporizing the liquid source by bubbling. A sub-heater 206a for heating the bubbler 220a and the liquid material inside is provided around the bubbler 220a. As the raw material, for example, TMA (trimethylaluminum, Al (CH ₃ ) ₃ ), which is a metal liquid raw material containing an aluminum (Al) element, is used.

A carrier gas supply pipe 237a is connected to the bubbler 220a. A carrier gas supply source (not shown) is connected to the upstream end of the carrier gas supply pipe 237a. Further, the downstream end of the carrier gas supply pipe 237a is immersed in the liquid raw material accommodated in the bubbler 220a. The carrier gas supply pipe 237a is provided with a mass flow controller (MFC) 222a as a flow rate controller for controlling the supply flow rate of the carrier gas, and valves va1 and va2 for controlling the supply of the carrier gas. As the carrier gas, a gas that does not react with the liquid raw material is preferably used. For example, an inert gas such as N ₂ gas, Ar gas, or He gas is preferably used. A carrier gas supply system (carrier gas supply line) is mainly configured by the carrier gas supply pipe 237a, the MFC 222a, and the valves va1 and va2.

  With the above-described configuration, the valves va1 and va2 are opened, the carrier gas whose flow rate is controlled by the MFC 222a is supplied from the carrier gas supply pipe 237a into the bubbler 220a, and the liquid raw material contained in the bubbler 220a is vaporized by bubbling to generate the raw material gas Can be generated.

<Raw gas supply system>
A raw material gas supply pipe 213a for supplying the raw material gas generated in the bubbler 220a into the processing chamber 201 is connected to the bubbler 220a. The upstream end of the source gas supply pipe 213a communicates with the space existing above the bubbler 220a. The downstream end of the source gas supply pipe 213a is connected to the gas inlet 210. The source gas supply pipe 213a is provided with valves va5 and va3 in order from the upstream side. The valve va5 is a valve for controlling the supply of the source gas from the bubbler 220a into the source gas supply pipe 213a, and is provided in the vicinity of the bubbler 220a. The valve va3 is a valve that controls the supply of the source gas from the source gas supply pipe 213a into the processing chamber 201, and is provided in the vicinity of the gas inlet 210. The valve va3 and a valve ve3 described later are configured as a highly durable high-speed gas valve. The high durability high-speed gas valve is an integrated valve configured so that gas supply can be switched and gas exhausted quickly in a short time. The valve ve3 is a valve that controls the introduction of purge gas for purging the inside of the processing chamber 201 after purging the space between the valve va3 of the source gas supply pipe 213a and the gas inlet 210 at high speed.

  With the above configuration, it is possible to supply the source gas from the source gas supply pipe 213a into the processing chamber 201 by opening the valves va5 and va3 while vaporizing the liquid source in the bubbler 220a. Become. A source gas supply system (source gas supply line) is mainly configured by the source gas supply pipe 213a and the valves va5 and va3.

  Further, a raw material supply system (raw material supply line) is mainly configured by the carrier gas supply system, the bubbler 220a, and the raw material gas supply system.

<Hydrogen-containing gas supply system>
In addition, a hydrogen-containing gas supply source 220b that supplies a hydrogen-containing gas that is a reducing gas is provided outside the processing chamber 201. The upstream end of the hydrogen-containing gas supply pipe 213b is connected to the hydrogen-containing gas supply source 220b. The downstream end of the hydrogen-containing gas supply pipe 213b is connected to the gas inlet 210 through a valve vb3. The hydrogen-containing gas supply pipe 213b is provided with a mass flow controller (MFC) 222b as a flow rate controller that controls the supply flow rate of the hydrogen-containing gas, and valves vb1, vb2, and vb3 that control the supply of the hydrogen-containing gas. ing. As the hydrogen-containing gas, for example, hydrogen (H ₂ ) gas or ammonia (NH ₃ ) gas is used. A hydrogen-containing gas supply system (hydrogen-containing gas supply line) is mainly configured by the hydrogen-containing gas supply source 220b, the hydrogen-containing gas supply pipe 213b, the MFC 222b, and the valves vb1, vb2, and vb3.

<Purge gas supply system>
Further, purge gas supply sources 220 c and 220 e for supplying a purge gas are provided outside the processing chamber 201. The upstream ends of the purge gas supply pipes 213c and 213e are connected to the purge gas supply sources 220c and 220e, respectively. The downstream end of the purge gas supply pipe 213c is connected to the gas inlet 210 through the valve vc3. The downstream end of the purge gas supply pipe 213e joins a portion between the valve va3 and the gas inlet 210 of the source gas supply pipe 213a via the valve ve3 and is connected to the gas inlet 210. The purge gas supply pipes 213c and 213e include mass flow controllers (MFC) 222c and 222e as flow rate controllers that control the supply flow rate of the purge gas, and valves vc1, vc2, vc3, ve1, ve2, and ve3 that control the supply of the purge gas. Each is provided. Further, for maintenance, a purge gas supply pipe 213f is connected via a valve vc4 between the hydrogen-containing gas supply source 220b of the hydrogen-containing gas supply pipe 213b and the valve vb1. The purge gas supply pipe 213f is branched from the portion of the purge gas supply pipe 213c between the mass flow controller 222c and the valve vc2. As the purge gas, for example, an inert gas such as N ₂ gas, Ar gas, or He gas is used. A purge gas supply system (purge gas supply line) is mainly constituted by purge gas supply sources 220c and 220e, purge gas supply pipes 213c, 213e, and 213f, MFCs 222c and 222e, and valves vc1, vc2, vc3, vc4, ve1, ve2, and ve3. Is done.

<Vent (bypass) system>
The upstream end of the vent pipe 215a is connected to the upstream side of the valve va3 of the source gas supply pipe 213a. Further, the downstream end of the vent pipe 215 a is connected to the downstream side of the pressure regulator 262 of the exhaust pipe 261 and to the upstream side of the raw material recovery trap 263. The vent pipe 215a is provided with a valve va4 that controls the flow of gas.

  With the above configuration, by closing the valve va3 and opening the valve va4, the process chamber 201 is bypassed through the vent pipe 215a without supplying the gas flowing in the source gas supply pipe 213a into the process chamber 201, Exhaust from the exhaust pipe 261 becomes possible. A vent system (vent line) is mainly configured by the vent pipe 215a and the valve va4.

Although the sub-heater 206a is provided around the bubbler 220a as described above, the carrier gas supply pipe 237a, the source gas supply pipe 213a, the purge gas supply pipe 213e, the vent pipe 215a, the exhaust pipe 261, the first A sub-heater 206a is also provided around the second processing vessel 202, the shower head 240, and the like. The sub-heater 206a is configured to prevent re-liquefaction of the source gas inside these members by heating these members to a temperature of, for example, 100 ° C. or less.

<Second control unit>
The second processing unit 32 according to the present embodiment includes a second controller 280 as a second control unit that controls the operation of each unit of the second processing unit 32. The second controller 280 includes a gate valve 251, an elevating mechanism 207b, a transport robot 273, a heater 206, a sub heater 206a, a pressure regulator (APC) 262, a vacuum pump 264, valves va1 to va5, vb1 to vb3, vc1 to vc4, and ve1. ˜ve3, controls the operations of the flow rate controllers 222a, 222b, 222c, 222e and the like.

(3) Substrate Processing Step Next, a substrate processing step of forming a metal film on the wafer 200 using the above-described substrate processing system as one step of the semiconductor device manufacturing process will be described mainly with reference to FIG. To do. FIG. 1 is a flowchart of a substrate processing process according to an embodiment of the present invention. In the following description, the operation of the first processing unit 31 is controlled by the first controller 180, and the operation of the second processing unit 32 is controlled by the second controller 280.

Here, a first pretreatment for terminating the surface of a titanium nitride (TiN) film as a first metal film formed on the wafer 200 with a hydroxyl group (OH group) is performed, and after the first pretreatment. An example in which a second pretreatment for supplying H ₂ gas as a hydrogen-containing gas is performed on the TiN film, and an Al film as a second metal film is formed on the TiN film after the second pretreatment. explain. The first pretreatment is performed using the first processing unit 31 described above, and the second pretreatment and the formation of the Al film are performed using the second processing unit 32 described above. The Al film is formed by supplying TMA as a raw material containing aluminum (Al) in the second processing vessel 202 to form an aluminum film (Al film) on the TiN film formed on the wafer 200. The process and the step of supplying the purge gas into the second processing container 202 and purging the inside of the second processing container 202 are defined as one cycle, and this cycle is performed a predetermined number of times. An example in which an Al film having a predetermined thickness is formed on a TiN film that has been processed will be described.

  In this specification, the term metal film means a film made of a conductive substance containing a metal atom, and includes a conductive single metal film made of a single metal. Also included are conductive metal nitride films, conductive metal oxide films, conductive metal oxynitride films, conductive metal composite films, conductive metal alloy films, conductive metal silicide films, and the like. The TiN film as the first metal film is a conductive metal nitride film, and the Al film as the second metal film is a conductive single metal film. This will be described in detail below.

<Substrate carrying-in process to first processing unit (S1), substrate support process (S2)>
Opening the gate valve 126 of the first processing unit 31 in FIG. 2A opens the substrate transfer port 124 of the cleaning apparatus main body 112 as the first processing container, and the wafer 200 to be processed by the substrate transfer device 127. Is carried into the cleaning chamber 114 (S1). Then, the substrate transfer device 127 is controlled to deliver the wafer 200 to the support 118, and the wafer 200 is supported by the support 118 (S2). After returning the substrate transfer device 127 to the outside of the cleaning chamber 114, the substrate transfer port 124 is closed by closing the gate valve 126. Thereafter, the rotation of the wafer 200 is started by rotating the support 118 via the rotation shaft 121 by the rotation mechanism 120. Note that a TiN film as a first metal film is formed on the wafer 200. The TiN film is formed by, for example, a CVD method, an ALD method, or a PVD method. On the surface of the TiN film, an oxide such as TiO ₂ or TiON is formed. As described above, a metal material such as Al has a property that it is difficult to adsorb on an insulating film made of an oxide or the like. The state of the surface of the wafer 200 loaded into the first processing unit 31 is illustrated in FIG.

<First Pretreatment Step (S3)>
[HF cleaning process (S3a)]
Subsequently, with the rotation of the wafer 200 maintained, the control valve 132 a is opened, and DHF is supplied from the cleaning liquid supply unit 128 toward the center of the wafer 200. At this time, the control valve 142 a is opened and pure water is supplied from the water supply unit 140 to the inner surface of the cover 122. As a result, the DHF blown to the inner surface of the cover 122 can be washed away. By opening the control valve 144a, the DHF supplied to the wafer 200 and the pure water supplied to the inner surface of the cover 122 are discharged to the outside through the drain pipe 144. At this time, the first pretreatment is performed on the wafer 200 by the DHF supplied onto the wafer 200. That is, by supplying DHF to the wafer 200, HF molecules and H ₂ O molecules contained in the DHF react with TiO ₂ , TiON, etc., which are oxides on the TiN surface formed on the wafer 200. Then, TiF ₄ , O _2, etc. are generated to remove TiO ₂ , TiON, etc., and the surface of the TiN film is exposed. Then, the exposed surface of the TiN film is terminated by OH groups. FIG. 7B illustrates a state in which the surface of the TiN film is terminated with OH groups.

[Rinsing step (S3b)]
When termination of the surface of the TiN film by OH groups is completed, the control valve 132a is closed while the rotation of the wafer 200 is maintained, supply of DHF from the cleaning liquid supply unit 128 is stopped, control valve 134a is opened, and rinse water is supplied. Pure water as rinse water is supplied from the unit 130 toward the center of the wafer 200 to wash away DHF remaining on the wafer surface. Also at this time, the control valve 142 a is opened, and pure water is supplied from the water supply unit 140 to the inner surface of the cover 122. As a result, the residual DHF blown to the inner surface of the cover 122 can be washed away. By opening the control valve 144 a, the washed-out DHF and the pure water supplied to the inner surface of the cover 122 are discharged to the outside through the drain pipe 144.

[Drying step (S3c)]
After washing away the DHF remaining on the wafer surface, the control valves 134a and 142a are closed with the rotation of the wafer 200 maintained, and the supply of rinse water from the rinse water supply unit 130 and the supply of pure water from the water supply unit 140 The rinse water on the wafer 200 is removed by centrifugal force due to rotation. At this time, the control valve 148a is opened, N ₂ as a drying gas is supplied from the drying gas supply source 148 through the drying gas supply pipe 146 into the cleaning chamber 114, and the cleaning chamber 114 is filled with an N ₂ atmosphere. The wafer 200 is dried in this N ₂ atmosphere. By opening the control valve 150a, N ₂ supplied into the cleaning chamber 114 is exhausted to the outside through the exhaust pipe 150. After the wafer 200 is dried, the rotation of the wafer 200 is stopped by stopping the rotation of the support 118 by the rotation mechanism 120. Further, the supply of N _{2 into} the cleaning chamber 114 is also stopped by closing the control valve 148a.

<Substrate Unloading Step from First Processing Unit (S4)>
Thereafter, the substrate transfer port 124 of the cleaning apparatus main body 112 is opened by opening the gate valve 126 of the first processing unit 31, and the wafer 200 that has been subjected to the first pretreatment by the substrate transfer machine 127 is removed from the cleaning chamber 114. Take it out. After unloading, the substrate transfer port 124 is closed by closing the gate valve 126. The wafer 200 that has been unloaded from the cleaning chamber 114 and has undergone the first pretreatment is transferred to the second processing unit 32. At this time, the surface of the TiN film formed on the wafer 200 is maintained terminated with OH groups. As will be described later, the surface of the TiN film is not in a state where Al is easily adsorbed only by being terminated by OH groups.

<Substrate Loading Step (S5), Substrate Placement Step (S6) to Second Processing Unit>
Subsequently, the wafer 200 for which the first pretreatment has been completed is carried into the load lock chamber of the second processing unit 32. The wafer 200 loaded into the load lock chamber is transferred from the load lock chamber into the transfer chamber 271 by the transfer robot 273. At this time, the lifting mechanism 207b is operated to lower the support table 203 to the wafer transfer position shown in FIG. Then, the gate valve 251 is opened to allow the processing chamber 201 and the transfer chamber 271 to communicate with each other. Then, the wafer 200 that has been subjected to the first pre-processing to be processed is transferred from the transfer chamber 271 into the processing chamber 201 by the transfer robot 273 while being supported by the transfer arm 273a (S5). The wafer 200 carried into the processing chamber 201 is temporarily placed on the lift pins 208 b protruding from the upper surface of the support table 203. When the transfer arm 273a of the transfer robot 273 returns from the processing chamber 201 to the transfer chamber 271, the gate valve 251 is closed.

  Subsequently, the elevating mechanism 207b is operated to raise the support table 203 to the wafer processing position shown in FIG. As a result, the lift pins 208b are buried from the upper surface of the support table 203, and the wafer 200 is placed on the susceptor 217 on the upper surface of the support table 203 (S6).

<Pressure adjustment step (S7), temperature adjustment step (S8)>
Subsequently, the pressure regulator (APC) 262 controls the pressure in the processing chamber 201 to be a predetermined processing pressure (S7). In addition, the power supplied to the heater 206 is adjusted to control the surface temperature of the wafer 200 to a predetermined processing temperature (S8). The temperature adjustment step (S8) may be performed in parallel with the pressure adjustment step (S7) or may be performed prior to the pressure adjustment step (S7). Here, the predetermined processing temperature and processing pressure are processing temperature and processing pressure at which an Al film can be formed by a CVD method in a raw material supply step (S10a) described later. That is, the processing temperature and the processing pressure are such that the raw material used in the raw material supply step (S10a) is self-decomposed. The predetermined processing temperature and processing pressure here are also the processing temperature and processing pressure at which the second pretreatment with the hydrogen-containing gas can be performed on the wafer 200 in the hydrogen-containing gas supply step (S9a) described later. .

In the substrate loading step (S5), the substrate placing step (S6), the pressure adjusting step (S7), and the temperature adjusting step (S8) into the second processing unit, the valve va3 is operated while the vacuum pump 264 is operated. , Vb3 are closed, and the valves vc1, vc2, vc3, ve1, ve2, ve3 are opened, so that the N ₂ gas always flows into the processing chamber 201. As a result, it is possible to suppress the adhesion of particles on the wafer 200.

<Second Pretreatment Step (S9)>
[Hydrogen-containing gas supply step (S9a)]
Subsequently, while the vacuum pump 264 is operated, the valves vb1, vb2, and vb3 are opened, and supply of H ₂ gas or NH ₃ gas as a hydrogen-containing gas into the processing chamber 201 is started. The hydrogen-containing gas is dispersed by the shower head 240 and is uniformly supplied onto the wafer 200 in the processing chamber 201. Excess hydrogen-containing gas flows through the exhaust duct 259 and is exhausted to the exhaust port 260 and the exhaust pipe 261. At this time, the wafer 200 is subjected to the second pretreatment by the hydrogen-containing gas supplied onto the wafer 200. That is, the OH group that terminates the surface of the TiN film on the wafer 200 reacts with the hydrogen-containing gas supplied into the processing chamber 201 to become H ₂ O and is removed from the surface of the TiN film. The film surface is terminated with hydrogen (H). FIG. 7C illustrates a state in which the surface of the TiN film is terminated with H. The surface of the TiN film is terminated with H, so that Al is easily adsorbed on the surface of the TiN film.

When supplying the hydrogen-containing gas into the processing chamber 201, the hydrogen-containing gas is prevented from entering the source gas supply pipe 213a, and the diffusion of the hydrogen-containing gas in the processing chamber 201 is promoted. The valves ve 1, ve 2 and ve 3 are preferably kept open, and the N ₂ gas is always allowed to flow into the processing chamber 201.

After the valves vb1, vb2, vb3 are opened and the supply of the hydrogen-containing gas is started, when a predetermined time has elapsed, the valves vb1, vb2, vb3 are closed, and the supply of the hydrogen-containing gas into the processing chamber 201 is stopped. Thereafter, with the valves (not shown) provided in the hydrogen-containing gas supply source 220b closed, the valves vc1, vc4, vb1, vb2, and vb3 are opened, and N ₂ gas is supplied into the hydrogen-containing gas supply pipe 213b. The inside of the hydrogen-containing gas supply pipe 213b is purged.

[Purge process (S9b)]
Thereafter, the processing chamber 201 is evacuated, the valves vc 1, vc 2, vc 3, ve 1, ve 2 and ve 3 are opened, and N ₂ gas is supplied into the processing chamber 201. The N ₂ gas is dispersed by the shower head 240 and supplied into the processing chamber 201, flows through the exhaust duct 259, and is exhausted to the exhaust port 260 and the exhaust pipe 261. As a result, the hydrogen-containing gas and reaction byproducts remaining in the processing chamber 201 are removed, and the inside of the processing chamber 201 is purged with N ₂ gas. By carrying out the purge step (S9b), it is possible to suppress the raw material gas supplied in the raw material supply step (S10a) described later from being mixed with a hydrogen-containing gas or the like. However, the purge step (S9b) is not necessarily performed.

  In parallel with the steps S1 to S9, the raw material (TMA) is vaporized to generate a raw material gas (preliminary vaporization). That is, by opening the valves va1, va2, va5 and supplying the carrier gas whose flow rate is controlled by the MFC 222a from the carrier gas supply pipe 237a into the bubbler 220a, the raw material contained in the bubbler 220a is evaporated by bubbling. A gas is generated (preliminary vaporization step). In this preliminary vaporization step, while the vacuum pump 264 is operated, the valve va4 is opened while the valve va3 is closed, thereby bypassing and exhausting the processing chamber 201 without supplying the source gas into the processing chamber 201. deep. A predetermined time is required to stably generate the source gas in the bubbler. For this reason, in this embodiment, the raw material gas is generated in advance, and the flow path of the raw material gas is switched by switching the opening and closing of the valves va3 and va4. As a result, it is preferable that the stable supply of the source gas into the processing chamber 201 can be started or stopped quickly by switching the valve.

<Al film forming step (S10)>
[Raw material supply step (S10a)]
Subsequently, the valve va4 is closed and the valve va3 is opened while the vacuum pump 264 is operated, and supply of the source gas (Al source) into the processing chamber 201 is started. The source gas is dispersed by the shower head 240 and uniformly supplied onto the wafer 200 in the processing chamber 201. Excess source gas flows through the exhaust duct 259 and is exhausted to the exhaust port 260 and the exhaust pipe 261. At this time, since the processing temperature and the processing pressure are set to a processing temperature and processing pressure at which the source gas is self-decomposed, the source gas supplied onto the wafer 200 is thermally decomposed to cause a CVD reaction. An Al film is formed on the wafer 200 that has been subjected to the pretreatment.

When supplying the source gas into the processing chamber 201, a valve is used to prevent the source gas from entering the hydrogen-containing gas supply pipe 213b and to promote the diffusion of the source gas in the processing chamber 201. It is preferable that vc 1, vc 2, and vc 3 are kept open, and N ₂ gas is always allowed to flow into the processing chamber 201.

  When a predetermined time has elapsed after opening the valve va3 and starting the supply of the raw material gas, the valve va3 is closed and the valve va4 is opened to stop the supply of the raw material gas into the processing chamber 201.

[Purge process (S8b)]
After the valve va3 is closed and the supply of the raw material gas is stopped, the valves vc1, vc2, vc3, ve1, ve2, ve3 are opened, and N ₂ gas is supplied into the processing chamber 201. N ₂ gas is
Dispersed by the shower head 240 and supplied into the processing chamber 201, flows through the exhaust duct 259, and is exhausted to the exhaust port 260 and the exhaust pipe 261. As a result, the raw material gas and reaction byproducts remaining in the processing chamber 201 are removed, and the inside of the processing chamber 201 is purged with N ₂ gas.

[Predetermined number of steps (S10c)]
The above-described raw material supply step (S10a) and purge step (S10b) are set as one cycle, and the second metal is formed on the TiN film subjected to the second pretreatment step (S9) by performing this cycle a predetermined number of times. An aluminum film (Al film) having a predetermined film thickness is formed as a film. In this embodiment, the raw material may be flowed not only in a pulse form but also continuously. In this case, the cycle of the raw material supply process and the purge process is performed once (in this case, the raw material is continuously supplied). Corresponds to the case).

[Residual gas removal step (S11)]
After an Al film having a predetermined thickness is formed on the wafer 200, the processing chamber 201 is evacuated, the valves vc1, vc2, vc3, ve1, ve2, and ve3 are opened, and N ₂ gas is supplied into the processing chamber 201. Supply. The N ₂ gas is dispersed by the shower head 240 and supplied into the processing chamber 201, flows through the exhaust duct 259, and is exhausted to the exhaust port 260 and the exhaust pipe 261. As a result, gas and reaction byproducts remaining in the processing chamber 201 are removed, and the inside of the processing chamber 201 is purged with N ₂ gas.

<Substrate Unloading Step from Second Processing Unit (S12)>
Thereafter, the wafer 200 after the formation of the Al film having a predetermined thickness is processed by a procedure reverse to the procedure shown in the substrate carry-in process (S5) and the substrate placement process (S6) described above. The substrate 201 is transferred from the chamber 201 into the transfer chamber 271, transferred from the transfer chamber 271 to the load lock chamber, and transferred from the load lock chamber to the outside of the second processing unit 32 to complete the substrate processing process according to this embodiment. To do.

The processing conditions for the wafer 200 in the second pretreatment step (S9) with the hydrogen-containing gas in the present embodiment are as follows:
Processing temperature (wafer temperature): 150 to 400 ° C.
Processing pressure (processing chamber pressure): 13 to 1333 Pa (0.1 to 10 Torr),
Hydrogen-containing gas (H ₂ gas or NH ₃ gas) supply flow rate: 0.1-5 slm,
Hydrogen-containing gas (H ₂ gas or NH ₃ gas) supply time: 10 seconds to 30 minutes,
Purge gas (N ₂ ) supply flow rate: 10 to 10,000 sccm,
Is exemplified.

Further, as the processing conditions of the wafer 200 in the Al film forming step (S10) in the present embodiment,
Processing temperature (wafer temperature): 150 to 400 ° C.
Processing pressure (processing chamber pressure): 13 to 1333 Pa (0.1 to 10 Torr),
Bubbling carrier gas supply flow rate: 10 to 1000 sccm,
(Aluminum raw material (TMA) gas supply flow rate: 0.1-5 slm)
Purge gas (N ₂ ) supply flow rate: 10 to 10,000 sccm,
Raw material (TMA) supply time per cycle: 0.1 to 600 seconds,
Purge time per cycle: 0.1 to 600 seconds,
Number of cycles: 1 to 400 times
Al film thickness: 10-200 nm
Is exemplified. Note that the processing temperature (wafer temperature) and the processing pressure (pressure in the processing chamber) are preferably constant in the second preprocessing step (S9) and the Al film forming step (S10).

  If the processing temperature is lower than 150 ° C. in the above processing pressure zone, the raw material (TMA) is not self-decomposed in the raw material supply step (S8a), and the film formation reaction by CVD does not occur. In addition, when the processing temperature exceeds 400 ° C. in the processing pressure zone described above, the film formation rate increases excessively, making it difficult to control the film thickness. Therefore, in the raw material supply step (S10a), the processing temperature needs to be 150 ° C. or higher and 400 ° C. or lower in order to cause a film forming reaction by CVD and control the film thickness. It has been confirmed that the second pretreatment can be performed on the wafer 200 in the hydrogen-containing gas supply step (S9a) within the processing pressure zone and the processing temperature zone. Therefore, in this embodiment, the second pretreatment step (S9) and the Al film formation step (S10) are performed by setting the same processing temperature zone and the same processing pressure zone. This eliminates the need to provide a process for changing the process temperature and a process for changing the process pressure between the second pretreatment process (S9) and the Al film formation process (S10), and throughput, that is, productivity. Can be improved. From the viewpoint of improving productivity, it is important to perform the second pretreatment step (S9) and the Al film formation step (S10) in the same treatment temperature range. The effect on sex is small. Therefore, in the second pretreatment step (S9), an optimum pressure zone for the second pretreatment may be selected.

According to the present embodiment, by performing the first pretreatment using the HF aqueous solution on the wafer 200 in the first pretreatment step (S3) before the second pretreatment step (S9), TiO ₂ , TiON, etc., which are oxides on the surface of the TiN film are removed, and the exposed surface of the TiN film is terminated with OH groups. Further, by performing a second pretreatment using a hydrogen-containing gas on the wafer 200 in the second pretreatment step (S9) before the Al film formation step (S10), the OH on the surface of the TiN film. The group is removed and the exposed surface of the TiN film is terminated with H. As a result, it is possible to create a state in which Al is easily adsorbed on the surface of the TiN film, and the initial nucleation density becomes dense in the Al film forming step (S10). As a result, a continuous film (low resistance film) in the thin film region ) Can be stably formed, and a high-quality Al film having a small surface roughness and a good surface morphology can be formed.

  In order to form a high-quality Al film, it is preferable that the surface of the TiN film serving as a base is terminated with H as described above. Therefore, the second pretreatment step (S9) is preferably performed immediately before the Al film formation step (S10). According to the present embodiment, the second pretreatment step (S9) and the Al film formation step (S10) are continuously performed in the same second treatment container 202. The processing step (S9) can be performed immediately before the Al film forming step (S10). If the second pretreatment step (S9) and the Al film formation step (S10) are performed in different processing containers, the state in which the surface of the TiN film is terminated with H is changed to the Al film formation step (S10). May not be maintained until the time of implementation.

In the above-described embodiment, either H ₂ gas or NH ₃ gas can be used as the hydrogen-containing gas. However, when H ₂ gas is used, a particularly great effect can be obtained. In addition, radical species or ion species generated by activating H ₂ gas or NH ₃ gas by an activation means such as plasma or heat can be used as the hydrogen-containing gas.

  In the above-described embodiment, the TiN film is used as the first metal film, but a tantalum nitride (TaN) film or the like may be used in addition to the TiN film. TaN is a conductive metal nitride film.

In the above-described embodiment, TMA is used as the metal raw material used for forming the Al film. However, in addition to TMA, TEAL (triethylaluminum, Al (C ₂ H ₅ ) ₃ ), TIBA (triisobutylaluminum, Al [(CH _{3) 2 CHCH 2] 3)} , DMAH ( dimethyl aluminum _{hydride, Al (CH 3) 2 H} ), DMEAA ( dimethylethyl aminoalane, (C
H ₃ ) ₂ C ₂ H ₅ N: AlH ₃ ) or the like may be used.

  In the above-described embodiment, the example in which the raw material gas is generated by bubbling the raw material gas has been described. However, the present invention is not limited to this, and the raw material gas may be generated by vaporizing the raw material with a vaporizer. Good.

  In the above-described embodiment, the example in which the Al film is formed using the CVD method for intermittently supplying the metal raw material has been described. However, the present invention is not limited to this, and the CVD method for continuously supplying the metal raw material or The Al film may be formed by using an ALD (Atomic Layer Deposition) method in which two or more gases are alternately supplied.

  In the above-described embodiment, the example in which the Al film is formed as the second metal film has been described. However, in addition to the Al film, ruthenium (Ru), tantalum (Ta), titanium (Ti), tungsten (W), cobalt ( When a metal film containing a metal element such as Co), nickel (Ni), hafnium (Hf), zirconium (Zr), molybdenum (Mo), iridium (Ir), platinum (Pt) is formed as the second metal film In addition, the present invention can be preferably applied.

<Other Embodiments of the Present Invention>
In the above-described embodiment, an example of forming a film using the single-wafer type CVD apparatus that processes one substrate at a time as the second processing unit 32 has been described, but the present invention is not limited to the above-described embodiment. . For example, the second processing unit 32 may be formed using a batch type vertical CVD apparatus that processes a plurality of substrates at a time. Hereinafter, this vertical CVD apparatus will be described.

  FIG. 6 is a schematic configuration diagram of a vertical processing furnace of a vertical CVD apparatus as the second processing unit 32 according to the present embodiment. FIG. 6A shows a processing furnace 302 portion in a vertical cross section, and FIG. Shows the processing furnace 302 portion in a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 6A, the processing furnace 302 has a heater 307 as a heating means (heating mechanism). The heater 307 has a cylindrical shape and is vertically installed by being supported by a heater base as a holding plate.

Inside the heater 307, a process tube 303 as a reaction tube is disposed concentrically with the heater 307. The process tube 303 is made of a heat-resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with the upper end closed and the lower end opened. A processing chamber 301 is formed in a cylindrical hollow portion of the process tube 303 so that wafers 200 as substrates can be accommodated in a state of being aligned in multiple stages in a vertical posture in a horizontal posture by a boat 317 described later.

  A manifold 309 is disposed below the process tube 303 concentrically with the process tube 303. The manifold 309 is made of, for example, stainless steel and has a cylindrical shape with an upper end and a lower end opened. The manifold 309 is engaged with the process tube 303 and is provided to support the process tube 303. An O-ring 320a as a seal member is provided between the manifold 309 and the process tube 303. Since the manifold 309 is supported by the heater base, the process tube 303 is vertically installed. A reaction vessel is formed by the process tube 303 and the manifold 309.

A first nozzle 333 a as a first gas introduction part and a second nozzle 333 b as a second gas introduction part are connected to the manifold 309 so as to penetrate the side wall of the manifold 309. Each of the first nozzle 333a and the second nozzle 333b has an L shape having a horizontal portion and a vertical portion, the horizontal portion is connected to the manifold 309, and the vertical portion is between the inner wall of the process tube 303 and the wafer 200. It is provided in an arc-shaped space so as to rise in the stacking direction of the wafer 200 along the inner wall above the lower part of the process tube 303. A first gas supply hole 348a and a second gas supply hole 348b, which are supply holes for supplying gas, are provided on the side surfaces of the vertical portions of the first nozzle 333a and the second nozzle 333b, respectively. The first gas supply hole 348a and the second gas supply hole 348b have the same opening area from the lower part to the upper part, and are provided at the same opening pitch.

  The gas supply system connected to the first nozzle 333a and the second nozzle 333b is the same as in the above-described embodiment. However, this embodiment is different from the above-described embodiment in that a source gas supply system is connected to the first nozzle 333a and a hydrogen-containing gas supply system is connected to the second nozzle 333b. That is, in this embodiment, the source gas and the hydrogen-containing gas are supplied by separate nozzles. The source gas and the hydrogen-containing gas may be supplied from the same nozzle.

  The manifold 309 is provided with an exhaust pipe 331 that exhausts the atmosphere in the processing chamber 301. A vacuum pump 346 as an evacuation device is connected to the exhaust pipe 331 via a pressure sensor 345 as a pressure detector and an APC (Auto Pressure Controller) valve 342 as a pressure regulator. By adjusting the APC valve 342 based on the detected pressure information, the processing chamber 301 is configured to be evacuated so that the pressure in the processing chamber 301 becomes a predetermined pressure (degree of vacuum). Note that the APC valve 342 is configured to open and close the valve to evacuate / stop evacuation in the processing chamber 301, and to adjust the valve opening to adjust the pressure in the processing chamber 301. Open / close valve.

  Below the manifold 309, a seal cap 319 is provided as a furnace port lid that can airtightly close the lower end opening of the manifold 309. The seal cap 319 is brought into contact with the lower end of the manifold 309 from the lower side in the vertical direction. The seal cap 319 is made of a metal such as stainless steel and is formed in a disk shape. On the upper surface of the seal cap 319, an O-ring 320b is provided as a seal member that contacts the lower end of the manifold 309. On the opposite side of the seal cap 319 from the processing chamber 301, a rotation mechanism 367 for rotating a boat 317 described later is installed. A rotation shaft 355 of the rotation mechanism 367 passes through the seal cap 319 and is connected to the boat 317, and is configured to rotate the wafer 200 by rotating the boat 317. The seal cap 319 is configured to be moved up and down in a vertical direction by a boat elevator 315 as an elevating mechanism disposed outside the process tube 303, and thereby the boat 317 is carried into and out of the processing chamber 301. It is possible.

  The boat 317 as a substrate holder is made of a heat-resistant material such as quartz or silicon carbide, and is configured to hold a plurality of wafers 200 in a horizontal posture and in a state where the centers are aligned with each other and held in multiple stages. Yes. A heat insulating member 318 made of a heat resistant material such as quartz or silicon carbide is provided at the lower part of the boat 317 so that heat from the heater 307 is not easily transmitted to the seal cap 319 side. A temperature sensor 363 as a temperature detector is installed in the process tube 303, and the temperature in the processing chamber 301 is adjusted by adjusting the power supply to the heater 307 based on the temperature information detected by the temperature sensor 363. Is configured to have a predetermined temperature distribution. Similar to the first nozzle 333a and the second nozzle 333b, the temperature sensor 363 is provided along the inner wall of the process tube 303.

  The controller 380 as a control unit (control means) includes an APC valve 342, a heater 307, a temperature sensor 363, a vacuum pump 346, a rotation mechanism 367, a boat elevator 315, valves va1 to va5, vb1 to vb3, vc1 to vc4, and ve1. The operation of ve3, flow rate controllers 222a, 222b, 222c, 222e and the like is controlled.

  Next, a substrate processing step of forming a metal film on the wafer 200 by the CVD method as one step of the semiconductor device manufacturing process using the processing furnace 302 of the vertical CVD apparatus according to the above configuration will be described. In the following description, the operation of each unit constituting the vertical CVD apparatus is controlled by the controller 380.

  A plurality of wafers 200 after the first pretreatment step (S3) is performed are loaded into the boat 317 (wafer charge). 6A, the boat 317 holding a plurality of wafers 200 is lifted by the boat elevator 315 and loaded into the processing chamber 301 (boat loading). In this state, the seal cap 319 is in a state of sealing the lower end of the manifold 309 via the O-ring 320b.

  The inside of the processing chamber 301 is evacuated by a vacuum pump 346 so that the inside of the processing chamber 301 has a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 301 is measured by the pressure sensor 345, and the APC valve 342 is feedback-controlled based on the measured pressure. In addition, heating is performed by the heater 307 so that the inside of the processing chamber 301 has a desired temperature. At this time, feedback control of the power supply to the heater 307 is performed based on the temperature information detected by the temperature sensor 363 so that the inside of the processing chamber 301 has a desired temperature distribution. Subsequently, the wafer 200 is rotated by rotating the boat 317 by the rotation mechanism 367.

  Thereafter, the second pretreatment step and the Al film formation step are performed in the same procedure as the second pretreatment step (S9) and the Al film formation step (S10) in the above-described embodiment. After an Al film having a predetermined thickness is formed on the wafer 200, the residual gas removal step is performed in the same procedure as the residual gas removal step (S11) in the above-described embodiment.

  Thereafter, the seal cap 319 is lowered by the boat elevator 315 to open the lower end of the manifold 309, and the wafer 200 after the Al film having a predetermined thickness is formed on the manifold 309 while being held by the boat 317. Unload from the lower end of the process tube 303 (boat unload). Thereafter, the processed wafer 200 is taken out from the boat 317 (wafer discharge).

  As described above, even when a batch-type vertical CVD apparatus is used as the second processing unit 32, it is possible to perform the same process as the substrate processing process according to the above-described embodiment, and the same as in the above-described embodiment. The effect of can be obtained.

  Examples of the present invention will be described below together with comparative examples. FIG. 8 is a diagram showing electron microscopic images (SEM images) of evaluation samples in examples and comparative examples of the present invention.

Example 1
FIG. 8A shows a surface image (SEM image) of the evaluation sample in this example. In this example, a substrate processing system described in the above-described embodiment is used for a wafer in which a SiO ₂ film having a thickness of 100 nm and a TiN film having a thickness of 10 nm are sequentially stacked on the surface, and a first HF solution is used. An evaluation sample was prepared by sequentially performing a pretreatment step 1, a second pretreatment step using H ₂ gas as a hydrogen-containing gas, and an Al film forming step using TMA as a raw material. And the surface of Al film | membrane of an evaluation sample was observed with the electron microscope (SEM observation).
The first pretreatment step, the second pretreatment step, and the Al film formation step are the process flow of the first pretreatment step, the second pretreatment step, and the Al film formation step in the above-described embodiment. As well as. In addition, the hydrogen-containing gas supply time in the second pretreatment process is 3 minutes, the raw material supply process in the Al film formation process is 1 second, and the purge process in the Al film formation process is 5 seconds. . Other processing conditions were set to values within the range of the processing conditions for each step in the above-described embodiment.

As shown in FIG. 8A, in this example, a continuous Al film having a thickness of 50 nm to 70 nm could be formed on the surface of the TiN film. This is because the first pretreatment step and the second pretreatment step are performed in this embodiment, and therefore, as shown in FIG. 7C, the TiN film immediately before the Al film formation step is performed. This is considered to be because the surface is exposed without being covered with an oxide such as TiO ₂ or TiON, is terminated with H, and Al is easily adsorbed. That is, it can be seen that by performing the first pretreatment step and the second pretreatment step, it is possible to create a state in which Al is easily adsorbed on the surface of the TiN film.

(Comparative Example 1)
FIG. 8B shows a surface image (SEM image) of the evaluation sample in Comparative Example 1. In this comparative example, after the first pretreatment process was performed on the above-described wafer, the Al film formation process was performed without performing the second pretreatment process, and an evaluation sample was created. The processing flow and processing conditions of the first pretreatment step and Al film formation step were the same as those in Example 1. And the surface of the evaluation sample was observed with the electron microscope (SEM observation).

As shown in FIG. 8B, in this comparative example, Al was formed in an island shape on the TiN film and did not become a continuous film. The thickness of Al was 0 to 20 nm. This is because the second pretreatment process is not performed in this comparative example, and as shown in FIG. 7D, the surface of the TiN film immediately before the Al film formation process is performed is made of TiO ₂ or TiON. Although it is exposed without being covered with an oxide, it is considered that it is in a state of being terminated with an OH group. That is, it can be seen that the state in which Al is hardly adsorbed on the surface of the TiN film is maintained only by performing the first pretreatment step of supplying DHF.

(Comparative Example 2)
FIG. 8C shows a surface image (SEM image) of the evaluation sample in Comparative Example 2. In this comparative example, the second pretreatment step and the Al film forming step were sequentially performed on the above-described wafer without performing the first pretreatment step, and an evaluation sample was created. The processing flow and processing conditions of the second pretreatment step and Al film formation step were the same as those in Example 1. And the surface of the evaluation sample was observed with the electron microscope (SEM observation).

As shown in FIG. 8C, in this comparative example, Al was formed in an island shape on the TiN film and did not become a continuous film. The thickness of Al was 0 to 20 nm. This is because the first pretreatment process is not performed in this comparative example, and therefore, as shown in FIG. 7E, the surface of the TiN film immediately before the Al film formation process is performed, such as TiO ₂ or TiON. It is thought that this is because the oxide is still formed. That is, it is not possible to remove oxides such as TiO ₂ and TiON only by performing the second pretreatment step of supplying H ₂ gas, and the state where Al is not easily adsorbed on the surface of the TiN film is maintained. You can see that

(Comparative Example 3)
FIG. 8D shows a surface image (SEM image) of the evaluation sample in Comparative Example 3. In this comparative example, a first pretreatment step, a second pretreatment step, and an Al film formation step are sequentially performed on a wafer in which a TiN film is not formed on the surface and Si is exposed. An evaluation sample was created. And the surface of the evaluation sample was observed with the electron microscope (SEM observation).

As shown in FIG. 8D, in this comparative example, the Al film could not be grown even if the first pretreatment step and the second pretreatment step were performed. In this comparative example, it is considered that the Si on the wafer surface was oxidized during the wafer transfer or the like, and the SiO ₂ film was formed on the wafer surface immediately before the Al film forming process. It is done. That is, it can be seen that even if the first pretreatment step and the second pretreatment step are performed, if the base immediately before the Al film formation step becomes an insulator, Al cannot be grown.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

According to one aspect of the invention,
Performing a first pretreatment for terminating the surface of the first metal film (TiN film) formed on the substrate with a hydroxyl group (OH group);
Supplying a hydrogen-containing gas to the first metal film after the first pretreatment and performing a second pretreatment;
Forming a second metal film on the first metal film after the second pretreatment;
A method of manufacturing a semiconductor device having the above is provided.

  Preferably, the step of performing the second pretreatment and the step of forming the second metal film are continuously performed in the same processing container.

  Preferably, the first metal film is a TiN film or a TaN film.

  Preferably, the second metal film is an Al film.

  Preferably, the first pretreatment is a treatment for removing an oxide on the surface of the first metal film (TiN film) formed on the substrate and terminating the surface with a hydroxyl group (OH group). .

  Preferably, the first pretreatment is a cleaning treatment of the surface of the first metal film with an HF aqueous solution.

  Preferably, the second pretreatment is a treatment in which the surface of the first metal film terminated with a hydroxyl group is terminated with hydrogen.

Preferably, the hydrogen-containing gas is H ₂ gas or NH ₃ gas.

According to another aspect of the invention,
A step of terminating the surface of the first metal film (TiN film) formed on the substrate with a hydroxyl group;
A step of hydrogen-termination of the surface of the first metal film terminated with a hydroxyl group;
Forming a second metal film on the first metal film terminated with hydrogen;
A method of manufacturing a semiconductor device having the above is provided.

According to yet another aspect of the invention,
A first processing container for processing a substrate;
An HF aqueous solution supply system for supplying an HF aqueous solution into the first processing vessel;
HF aqueous solution is supplied to the substrate housed in the first processing container to terminate the surface of the first metal film (TiN film) formed on the substrate with a hydroxyl group (OH group). A first controller that controls the HF aqueous solution supply system to perform processing;
A second processing container for processing the substrate;
A hydrogen-containing gas supply system for supplying a hydrogen-containing gas into the second processing vessel;
A source gas supply system for supplying a source gas into the second processing vessel;
A hydrogen-containing gas is supplied to the substrate accommodated in the second processing container to perform a second pretreatment on the first metal film after the first pretreatment, and then to the substrate On the other hand, the hydrogen-containing gas supply system and the source gas supply system are controlled so as to supply a source gas and form a second metal film on the first metal film after the second pretreatment. A second control unit;
A substrate processing system is provided.

101 1st processing container 180 1st controller (1st control part)
200 wafer (substrate)
280 Second controller (second controller)

Claims (7)

Performing a first pretreatment for cleaning the surface of the first metal film formed on the substrate with an aqueous HF solution and terminating with a hydroxyl group;
Supplying a hydrogen-containing gas to the first metal film after the first pretreatment and performing a second pretreatment;
Forming a second metal film on the first metal film after the second pretreatment;
Have
The method of manufacturing a semiconductor device, wherein the first metal film is a TiN film or a TaN film, and the second metal film is an Al film.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the step of performing the second pretreatment and the step of forming the second metal film are continuously performed in the same processing container. .   3. The process according to claim 1, wherein the first pretreatment is a process of removing an oxide on a surface of the first metal film formed on the substrate and terminating the surface with a hydroxyl group. The manufacturing method of the semiconductor device of description. The second pre-processing method for forming a semiconductor device according to any one of claims 1 to 3 The surface of the first metal film hydroxyl terminated characterized in that it is a process of hydrogen termination. The method of manufacturing a semiconductor device according to any one of claims 1 to 4, wherein the hydrogen-containing gas is H ₂ gas or NH ₃ gas. Performing a first pretreatment for cleaning the surface of the first metal film formed on the substrate with an aqueous HF solution and terminating with a hydroxyl group;
Supplying a hydrogen-containing gas to the first metal film after the first pretreatment and performing a second pretreatment;
Forming a second metal film on the first metal film after the second pretreatment;
Have
The substrate processing method, wherein the first metal film is a TiN film or a TaN film, and the second metal film is an Al film. A first processing container for processing a substrate;
An HF aqueous solution supply system for supplying an HF aqueous solution into the first processing vessel;
A first pretreatment in which an aqueous HF solution is supplied to the substrate accommodated in the first processing container to terminate the surface of the first metal film made of TiN film or TaN film formed on the substrate with a hydroxyl group. A first control unit for controlling the HF aqueous solution supply system to perform
A second processing container for processing the substrate;
A hydrogen-containing gas supply system for supplying a hydrogen-containing gas into the second processing vessel;
A source gas supply system for supplying a source gas into the second processing vessel;
A hydrogen-containing gas is supplied to the substrate accommodated in the second processing container to perform a second pretreatment on the first metal film after the first pretreatment, and then to the substrate On the other hand, the hydrogen-containing gas supply system and the source gas supply so as to form a second metal film made of an Al film on the first metal film after the second pretreatment by supplying a source gas. A second control unit for controlling the system;
A substrate processing system comprising: